Watering of the eyes when looking at the sun or bright light is usually due to light sensitivity (photophobia). Bright light stimulates the nerves in your eyes, causing reflex tearing to protect them. It can happen if you have dry eyes, eye strain, a mild allergy, or are spending too much time on screens. Wearing sunglasses outdoors and using lubricating eye drops may help. If you have frequent discomfort, it is best to see an eye doctor for a check-up.